Photographer Jill White posted the photo of her daughter Willa's bathing suit being pulled down in jokey recreation of the famous 'Coppertone girl' pose from the 1950s ad campaign.
But someone complained to the social media giant which said Jill had fallen foul of its strict guidelines on posting nude children, and suspended the mum from the site for a day after she ignored a request to remove an unedited version of the photo.
Jill then replaced that picture with a version that has a smiley face emoticon over the toddler's semi-bare behind instead.
Jill said: "I got back on with another photo, this time a big Emoji face on the area of the butt crack."
That was also reported – however, Facebook said that this picture meets its terms and conditions.
The original Coppertone advertisement showed a little girl's swimming costume being pulled down by a small dog, to expose her bum.
Jill said she was at the beach recently near her home in Hickory, North Carolina, when she decided to recreate it. Jill told local news: "I posted the photo on Coppertone's Facebook. We thought it would be cute because of the old Coppertone ad and her tan line looked like that."
Facebook defended its action, saying: "It is hard. With over 1 billion people using Facebook we have to put in place a set of universal guidelines that respect the views of a wide range of people.
"These policies are designed to ensure Facebook remains a safe, secure and trusted environment for everyone on Facebook.
"Facebook has a strict policy against the sharing of pornographic content and any explicitly sexual content where a minor is involved.
"We also impose limitations on the display of nudity. We aspire to respect people's right to share content of personal importance."
Jill said neither of the photos she posted should be considered pornographic.
She said: "I despise pornography and anything to do with it. I would never ever post a pornographic photo. I am anti-porn."
The row echoes another story over the weekend when Instagram deleted mum Courtney Adamo's account after she shared a photo of her young daughter Marlow pulling up her top to show her bare tummy.
Instagram said the photo was 'inappropriate'.
Mum-of-four Courtney, who runs the site Babyccino, wrote on her blog: "I went back to re-read the guidelines. I read the entire page twice and was positive that I had not violated any rules. Unless a baby's belly is considered 'nudity'... but surely it isn't! She is a BABY!
"It is no different than a photo of a baby wearing a nappy, or a little boy in swim trunks, and to entertain the idea that it is even remotely inappropriate is a disgusting thing in itself."
Thankfully, after a social media backlash, Instagram reinstated Courtney's account, with the explanation: "We try hard to find a good balance between allowing people to express themselves creatively and having policies in place to protect young children.
"This is one reason why our guidelines put limitations on nudity, but we recognize that we don't always get it right. In this case, we made a mistake and have since restored the account."